I'm using a Audio-Technica lav Series 1400 lav system and it sounds really nice.

As for an amp, I tried the Passport P-250, but had to return it; the system does not have an actual equalizer, only a tone control, and even with the help of a pro sound mixer, we couldn't get a clear, crisp sound. Now I'm using the Peavy Escort and couldn't be happier. It has a graphic equalizer, seperate controls for hi and low tones, all the standard bells and whistles, plus it all packs together to make a golf bag-sized trunk on wheels. Still heavy as shit though.

The transmitter on my mic is fucked, it has been serviced twice under warrenty and it is obvious that the part is defective. It is acting up once more and they want to service it AGAIN rather then replace the unit. My warrenty is expired now but they "may" do something for me. The unit has been sent in again (during peak season) for them to look at before they decide that it is my fault that it doesn't work.